openmaps is a nice app to work with openstreetmaps. nice UI, everything is fine as long as you are online. Openstreetmaps contain more detail than google maps, at least in my trials.
problems are following:
offline map downloading is absolutely slow, unbearable, it only works with small towns. If you do it for a larger area, for me it is impossible. could take days.
in order to download, you have to specify the zoom level. the amount of data depends on the the zoom level, that goes from a few MB to 200 or 3000 MB. It is absolutely unclear which level you need to view eg. street names or POI icons.
online searching - if i search a location in my country(eg. germany), it always finds a similar name in the US and other countries and i get a display of the whole world map instead of the zoomed in location i am searching. i have to zoom in all manually. Google is much better on this point.
franzt2000 about OpenMaps Pro, v4.5.2